Method of forming and handling dipped formed articles



Aug. 17, 1937.

E. T. FERNGREN METHOD OF' FORMING AND HANDLING DIPPED FORMED ARTICLES Original Filed Aug. 20, 1952 5 Sheets-Sheet l Aug. 17, 1937. E. T. FERNGREN METHOD OF FORMING AND HANDLING DIPPED FORMED ARTICLES Original Filed Aug. 20, 1932 5 Sheets-Sheet 2 l NL. )55 56 'INVENTOQ E. T. FERNGREN METHOD OF FORMING AND HANDLING DIPPED FORMED ARTICLES Aug.' 17, 1937. f

3 Sheets-Sheet 3 Original Filed Aug. 20, 1932 Snoemor Patented Aug. l?, 1937 METHOD OF FDRMING AND HANDLING DIPPED FORD/IED ARTICLES Application August 20, 1932, Serial No. 629,697 Renewed July l, 1936 Claims.

This invention relates to improvements in the manufacture of film objects made by dipping processes, from various plastics and colloidal solutions or dispersions.

The composition from which dipped form objects are produced may comprise nitro-cellulose and/or cellulose acetate, also other forms of cellulose derivatives to which solvents and plasticizers may be added in suitable proportions to produce solutions or dispersions of viscid nature from which coatings may be obtained by dipping procedure, the coating obtained on the dipping tool forming a solid lm thereon when the solvents have been evaporated.

These coatings may be soft, pliable and eX- tensible or relatively hard and brittle depending upon the amount of plasticizers of different nature which are added -to the baseiof the material and the proportions of resins or gums blended therewith. In this relation different solvents should be selected for their particular actions on the various materials blended so as to produce the proper degree of progressive evaporation during the drying oi; the nlm, also, all solvents used should be compatible with the materials composing the solution so that practically uniform suspensions and blends may be had. Many formulas are vavailable which will afford sufcient data as to proper compositions with regard to the particular properties required in the film.

Latex compositions likewise form and provide excellent materials for the forming of films with very elastic properties serviceable for many purposes.

The present invention, as to the speciiic item shown, is directed to the production of petticoat or over-all milk bottle caps, however many other hollow articles may be formed by the 40 process herein brought out.

The successful automatic production of an item such as the milk bottle cap from the materials hereinabove noted by the dipping process depends in a large degree upon the ease and accuracy by 45 which the solidied coating may be removed from the dipping tool, as it is essential that the bottle process steps which make possible a perfect removal of the iilm object in open form from the dipping tool in a uniform shape with a neatly trimmed edge, without the employment of steam, or water in the operation of removing the cap.

in the accompanying drawings,

Figure l is a vertical section taken through the mechanism employed in carrying out the main feature of the process.

Figure 2 is a fragmentary View principally in side elevation of a plurality of dipping tools and associated mechanism mounted on a common support for simultaneous operation.

Figures 3, 4 and 5 are fragmentary showings of l that portion of the mechanism which is mainly employed as the coating tool showing it in different relationships to the plastic solution during association therewith. l

Figure 6 illustrates the angular position of the dipping tool during rotation directly following removal from the plastic solution.

Figure '7 illustrates a suitable position of the tool while it is rotated around its axis during solvent removal from the iilm and shows an associated drying means in section.

Figure 8 is a fragmentary View partly in section of the dipping tool showing the position of the film wall as it is being lifted away from the tool.

Figure 9 is a fragmentary View partly in section of all of the parts associated during the removal of the cap.

Figure 10 is an elevational view partly in section showing the parts associated at the instant of completed forming of the film object and the cutting thereof from the stripping member.

Figure 11 is a view in vertical section showing the delivery of caps and their nesting.

Figure 12 is a side elevation partly in section of the mechanism employed during the nesting procedure.

Figure 13 illustrates a modified type of relationship between a stripping device and the forming tool proper.

Figure lli indicates the film Wall being moved from the dipping tool surface.

Figure 15 is a view partly in elevation and partly in cross section of parts associated in the mcdiiied form of the device.

Figure 16 is a perspective view in cross section of the finished cap after remo-val from the dipping tool.

Illustrating the method steps employed in the several iigures only enough of the machine elements are shown which are directly concerned in the process, all other operating parts required not being 'per se a part of the present invention. 1 Certain Vof these other elements are disclosed in my Vcopending application, Ser. No. 632,689, :tiled September 12, 1932, which is in part a continuation ofthe present invention. Y

A dipping tool I1 upon which the cap is initialiy formed is attached to a hollow shaft I8 which is journaled in a hub element I9 of cross by mechanism adapted to move the beam 26 and a stripping cup 21 along shaft I8 upward or downward along the shaft I8 as may be required, the cup 21 beingv rotatably mounted with respect to the web portion v2B of the beam 26 `by means of a recess 29 which is of annular shape, formed in the hub portion 30 of the cup, so that the cup portion 21, which is splined to the shaft I3 and free to slide vertically thereon by means of the slotted guide way 3i, may be free' to rotate with the shaft I8 and the dipping tool I1 while being movable downward or upward on the outside of the dipping tool.

The tool I1 and the stripping cupy 21 are both cylindrical in shape, the periphery of the tool fitting closely the insideof the cup 21 as shown Air may be admitted to the interior space 33 Y of the dipping tool and the space 34 within the stripping cup 21 by means of the bore 35 in theV shaft i8 the air supply being admitted in said bore froma pipe member 36 and nipple 3i. This air maybeheated or cooled atcertain periods during the drying stage or coagulation of theA film as may be desired. Y

During association of the dipping tools with the plastic solution 38 the tool is initially tilted at an angle such as that indicated in Figure 3 r and may be simultaneously rotated during its submersion to a depthsuch as that indicated in Figure 4. At the instant of completed subvmersion the lower edge 39 of the cup 21 is moved deeper into the solution by a slight downward movement of the member 26. The object of V'this movement is to form a film wall coating on y Cil the inner surface of the stripping member 21 adjacent to its low-er terminusY for the purpose of providing a iilm wall extension from the normal edge portion of the lm on the tool I1 which will lie in the direction of subsequent movement of the cup 21. While such film wall coating 4D will be of slight extent, it serves as a bridging release of the lmfrom the tool .which will YYbe hereafter more fully explained.

The dipping tool is moved into the position indcated in Figure while emerging from the pcol 38 and almost immediately thereafterv is brought'into the positions shown in Figures 6 and 7 while constantly being rotated in one direction Y or' the other.

Atrthis instant the suction member 4I may be located as indicated to cause a movement on air past the lm surface of the dipping tool I1, the air being evacuated from the interior space 42 by means of suitable evacuating mechanism operating through suitable connections comprising, for example, conduit parts,

43 and 44. The solvents removed from the film may be recovered in the usual fashion by any suitable recovery system. Y

After the film body on the forming tool has been properly solidified the cup 21 is moved `Voutwardly or downwardly over the forming tool in the direction of the nlm membrane 40 at the inner edge of the cup, thus causing this film portion 40 to act as a pliant pulling vehicle on the upper edge of the film on the dipping tool, moving Ythe upper film wall section 45 off .the tool in the direction of the movement of the cup edge 39 and reversing the film as shown in, Figure 8.

As the stripping cup 21 continues to move outwardly the required distance to complete the removal of the film wall portion 45 from theside wall 46 of theY dipping tool I1, a hollow receiver ing head 41 carried by a hollow shaft 48 is moved into the proximity of. the film wall on the dipping tool, as shown in Figure 9, the lower end 49 of the receiving head being shaped similarly to the. Yupper bead edge of the mouth of a'milk Vbottle and the cap receiving end of the member 41 being suitably shaped to accommodate the caps being formed, so when film wall 45 has been completely reversed it will also have complete support of form retaining nature. This is best shown in Figure Where the film wall is shown as completely reversed and transferred from the dipping tool to the receiving head. At this instant a rotary cutting or trimming member 52 is moved to bring its shearing edge 53 to position to trim or cut the edge wall portion 40 from that portion of the iilm Wall which forms the`- outwardly turned section 54 (Figure 11) finished milk bottle cap.

The cutting knife 52, during association with the film wall, isArotatedfand also advanced into a penetrating contact with the film body by a movementV of the sleevef55 which carries both the cutting knife 52 andthe gear member 56. i

The gear 56 is intermeslhed with adjoininggears all of which rotate together. The mechanism described insures a very clean cutting action on of. the Y the lm as the annularl knifeVV edge V53 bears. Y

against the stretched or radiallyjtensioned film` section which spans the open space between the edge 39 of stripping member V21 and upper Wall portion 51 of the receiving head 41. The point where the knife edge 53 cleaves through the rllm.y

body is approximately where the surplus wall portion 40 joins the film initially formed on theY dipping tool I1. Y

During the Voutward movement of the stripping,

'cup 2i air is admitted into the bellow interior 33 of the dipping tool as indicated by arrow 58 (Figure 9), this air escaping through Vthe bore 59 into the space 60the air moving throughraV clear? ance space 62 rbetween the outer periphery 32 of the dipping tool and the inner face of the J stripping cup 21, into the space 6I rearward of I the lm wall and assisting in pressing theV `1ilm wall against the side wall 63 of the hollow receiving head 41 and also providing a pneumatic cushion back of the film as itis being cut attached to the end Wall portion68 of the head 4'! by exhausting air trapped therebetween through the passages 69 in the wall 68 to the interior Sil of. the head which is evacuated as above set forth, so that when the surplus film 40 is trimmed off, the cap is neatly transferred to the head 61. The head 5'! is then moved outwardly from association with the dipping tool I l.

The linished cap carried by the member 4'! is now moved to a position as indicated in Figure l1 where the cap is released therefrom by the simple expedient of restoring normal atmospheric pressure in the cavity 6d of the head. Sometimes when the film cap material is inclined to be adhesive in its properties a slight amount of air pressure established in the cavity 64 will operate through the passages 69 forcibly to dislodge the film cap therefrom, the air being introduced through the passage @5 as indicated by the arrow lli and uniformly concentrically distributed behind the cap structure as indicated by the several arrows 7l.

A finished milk bottle cap 14 is thus released from the member 47, at a time when a receiving head 73 or the caps 14 already located on said receiving head are in a position to receive the oncoming caps which are being nested by this procedure in a paper tube 15 held by a concentric cylindrical member 16. The receiving head 'I3 is caused to recede downward a short distance within the paper tube 15 as each cap is delivered there-into until a certain number of caps have been received in the tube and the head i3 passes out of the holding member 16. At this time the lower end 7'! of the receiving head coacts with a crank 18 to cause the indentation of the paper tube 'l5 by plunger members i9, which are caused to advance and indent the side of the paper tube l5 at Si! as shown in Figure 12, by the forward actuation of. the plunger 7E! in a slotted member 8|. 'Ihe crank 'i8 is normally held in a withdrawn position by a tension spring 82, the lower end of the crank being arranged as to freely permit the entry of the member i3 into the casing 'i6 withf out becoming operatively active on the plunger 'i9 as indicated by the dotted lines in the drawings.

Figures 13, 14 and l5 illustrate a slightly simpliiied arrangement where the lower periphery 39 of the stripping tool 2'! is formed as a cutting edge 83 for trimming the iilm as it is being stripped. T'he edge 83 cooperates with the flange 8d of the receiving head 41a to trim the edge of the milk bottle cap. The operation in this instance may be performed without any turning movement of the cutting edge, or of the surface 84 of the member 41a. However, the dipping tool and stripping cup may be rotated at the instant of penetration of the edge 83 to the film j body d5 which will immediately entirely separate the cap from the dipping tool, all of the parts being otherwise organized as heretofore described. The air employed to facilitate the operation may be heated or cooled as required, as

. suited to different plastic materials for the purpose of temporarily modifying the extensibility of the film so that it may be properly cohesive and firm in its body structure during handling.

It should be noted that the application of the air and vacuum at different points of the film The reason for the rotation of the vdipping tool l1, at time of submersio-n into the plastic s'olution, and the angular approach of the tool, is to prevent inclusion of air at the annular corner formation in the lower face of dipping tool when coating same.

'I'he object of the angular tilt of tool Il' at time of departure from the plastic solution is. to quickly drain surplus plastic away from the tool and to promote rapid spreading of the plastic accumulation as the tool is withdrawn from contact with the solution. The reason for depressing the-lower edge 39 of the stripping cap 21, when the tool i'! is in dip, is to avoid. inclusion of air at the upper end of the iilm,.when coating the inner side of edge 39 and forming the surplus wall fill.

The result of this manipulative treatment of the film body structure of the cap is toremove the same without in any way disturbing or distorting its structure and this process of operation and of treatment can be employed with equal certainty over a wide range of hollow dip formed articles when removing same from dipping tools as may readily be understood by those skilled in the art.

While I have herein shown and described a. certain practical embodiment of the invention suitable for carrying out the manipulative ste-ps; and treatments thereof I do not limit the method to use only by the particular form of construction herein presented.

I-Iaving thus described my invention I desire to claimz- 1. The method of making dip-formed coatings with dipping tools, which comprises rotating a forming tool in plastic film-forming material and simultaneously forming a surplus coating on the inner wall of a stripping m-emeber closely adjacent to the dipping tool, such coating being connected with and approximately p-aralleling the coating on the dipping tool, and then removing the coating from the dipping tool by causing the coating thereon to reverse and follow in the direction of the surplus film as such film is being removed by the stripping member.

2. The method of removing lm. objects from dipping tools and of uniformly trimming the edge of the film, which comprises creating a surplus film section extending from the filmonthe dip` ping tool and about a'cutting edge of a cylindrical member, relatively moving the tool in respect to thecylindrical member and thus causing the separation of the iilmv from the tool, and moving the cutting edge of the cylindrical member against a surface distant from the dipping tool to trim Athe `edge of the iilm formed as aforesaid.

3. The method of producing hollow film articles, comprisingthe steps of dipping a forming member into a plastic film-forming material, thereafter stripping the formed iilm. from the member by first removing that portion of the lm which is to form the side wall of the article, then bringing a receiving head into proximity with the partly stripped film and attaching the receiving head to the unstripped portion of the film, trimming the outer edge of the side wall of the film by the operation of a cutting' edge associated with the receiving head, and then completing the removal of the film from the forming member.V

4. In the making of hollow iilm articles by dipping process wherein a film, coating is formed and solidified on a dipping tool, the `pro-cess of removing said film from. the tool 'to produce the article, which comprises using air pressure on one side of the film'and vacuum| action on the other to move the film away from the tool and during this action shearing the film to produce an vedge portion on the article to liberate the Y same from the tool.

5. In'the making of hollow film articles by dippingV wherein a film is solidified on a dippingj r the position of the edge'portion Irelative the central portion, and thereafter cutting the film. from its edge support and removing it fromithe dipping tool.

V6.1'I'he process of producing hollow articles v 's-0 from solutions of materials in solvents, whichl Cal comprises submerging a forming implement with the smallv end foremost and at a constantly changing angle, first, cornerwise into the top layer of such solution while moving successive points of the corner area of the implement rotationally to secure a tangentially sweeping progressive immersion Yof the foremost surfaces of Vthe implement, thenr into aperpendicular position to attain the required depth of submersion, thence outward away from. the solution while resuming a cornerwise relationship for drainage of material from the implement, arresting the draining by rotating the implement at the speed which will cause a pick-up of the draining material, thereafter varying Vthe angular position of the implement while exposing the coating to suctionalaction to remove solvents and solidify the material, thereafter progressively reversing the coating by drawing it outward over the implement with its inner side turned outward, and trimming itsedge portion and removing it as a `hollow article.

'1. The method of forming a hood cap with a recess in its top end, which comprises drying a Ii lm forming coating onrthe outside of aforming tool which is shaped to form a film cap with a raised portion at its top end, then shaping the said film to produce the recess Vat its top end by changing the position of the side portion of the said film on the tool relative to the position of the raised portion, the said shaping ,consisting in turning the side wall forming film'portion and moving it into a position which is the reverse of its prior position relative. to the top forming film portion on'the tool, then taking the said top film Vportion for the cap away from the tool without changing its form or reversing its position relative the new position of the said side wall lm, and thereby completing the forming of the said cap with a recess in its top end,

8. V'Ihe method of forming hood caps for bottles which comprises forming a film-body for the cap on a slightly tapered cap-tool which will permit Athe reversal Vduring'removal of the side Wall of the said lm-'body by turning it inside out, forming the cap from said lm-body by changing the position of 'the sidewall and shoulder' portion of the film-body relative to the top wall section thereof, during'such reversal from the tool of the side wall film-body, trimming off and discarding a marginal portion of said side wall film body to form a uniformk edge portion for,

the cap, and during said procedures causing air under pressure to remove'the lm from contact with the said cap-tool.

centrically spaced surface to the surface of theV implement, solidifying the continuous coating on the said parts, Vmoving the reversing means and thecoating thereon outward over the implement,

in so doing progressively turning a portion ofthe said coating on the implement inside out while moving the forward portionthereof to a point beyond the implement, during the nal movement of removal while the outer edge of the said reversed coating is supported from the Y coating formed on the substantially parallel suri'ace of the said medium, severing the coating at Vthe said edge to separate it from the supporting coating, and during said procedure causing air under pressure to impart rigidity to the coating at the line of severance.

10..A Thek method of producing caps for bottles from materials which form cohesive lms, whichV comprises applying a coating of such material to an implement which has the required shape, treatingl the coating on the implement to obtain a cohesive film structure, moving that portion of film which is to form the side wall of the cap so it will be turned inside out, during thisv action supporting the reversing film fromr its outer limits and also from its central portion, releasing theY central portion of the nlm from the said implement by means of air pressure while thus supported, and then trimming the edge of the film and taking it away from the implement as a completed cap.

11. The method of forming caps for-bottles which comprises applying a coating of nlmforming materials onto the surface of a preliminary former and solidifying it thereat, then forming the cap by the following steps, first by mechanically and pneumatically reversing, freeing and drawing that portion of the coating which forms the sidewall of the cap away from` the preliminary former, second, by receiving the reversed portion of the coating ona take-01T devicehaving the shape of the bottle cap, third,

Y by causing air to operatev between that portion of the coating whichforms the top portion of the cap` and the corresponding portion of the preliminary former while the take-off device is in receiving position and, fourthby cutting the coating adjacent to its marginal edge it from the preliminary former.

12. In the process of removing hollow-nlm ticies from dipping tools, the steps whichcomprise bending Vbackwardly the peripheral margin of such a film article away from the dipping tool upon which .said article was formed and applying air pressure betweenthe film wall and said dipto free ping tool, and applying air pressure in the space between said slidable sleeve, said dipping tool and said peripheral margin of said film.

14. In the process of removing hollow-lm articles from dipping tools, the steps which comprise bending backwardly the peripheral margin of such a lm article away from the dipping tool upon which said article was formed, applying air pressure between the lm wall and said dipping tool, and applying vacuum on the opposite side of the lm wall, the air pressure and vacuum jointly assisting in the stripping of the lm from the dipping tool,

15. In the process of removing hollow-lm articles from dipping tools, the steps which comprise bending backwardly the peripheral margin of such a iilm article away from the dipping tool` ENOCH T. FERNGREN. 

